The present invention relates generally to monolithic microwave integrated circuits (MMIC) devices, and more particularly, to flip chip MMIC devices formed on Gallium Arsenide that employ thermally bumped diode and field effect transistor (FET) devices.
Flip chip technology involves methods used to interconnect semiconductor die to a host substrate. Generally, bumps (solder, or hard plated bumps) are used in place of wirebonds for I/O connections. Flip chip bump interconnection technology is a concept that has been around for many years. Most of the past work in this technology area has concentrated on the use of solder bump technology in conjunction with silicon-based integrated circuits.
The closest known prior art relating to the present flip chip limiter is a conventional face-up limiter MMIC device. The closest known prior art relating to the present transmit/receive switch is a conventional face-up transmit/receive switch MMIC device. The limiter and face-up transmit/receive switch MMIC devices require full wafer processing, including costly backside processing such as wafer thinning, along with via and backside metallization. Because this design is based on conventional microstrip transmission line media, the performance of this circuit is very sensitive to backside processing, especially wafer thinning. Finally, and most importantly, gallium arsenide is not an excellent thermal conductor. Under high incident RF conditions, large amounts of heat will be seen at the locations of active devices. This heat must then be dissipated through the gallium arsenide. It is this heat dissipation limitation which limits the power protection capability of the prior art.
Accordingly, it is an objective of the present invention to provide for improved flip chip MMIC devices formed on Gallium Arsenide that employ thermally bumped diode and field effect transistor (FET) devices. It is a further objective of the present invention to provide for improved flip chip limiter monolithic microwave integrated circuits formed on Gallium Arsenide employing thermal bumped diode devices. It is yet another objective of the present invention to provide for improved transmit/receive switch monolithic microwave integrated circuits formed on Gallium Arsenide employing thermal bumped FET devices.